As is known, in a logically partitioned data processing system, the resources of the system are partitioned into a plurality of logical partitions enabling a multitude of system control programs (e.g., operating systems) to run simultaneously in the different partitions. One embodiment of a logically partitioned data processing system is described in U.S. Pat. No. 4,843,541, entitled "Logical Resource Partitioning of A Data Processing System," Bean et al., issued on Jun. 27, 1989 and assigned to International Business Machines Corporation, which is hereby incorporated herein by reference in its entirety.
Each logical partition of a logically partitioned data processing system has its own resources, including for example, main storage, expanded storage, channels and subchannels, and thus, operates independently of the other logical partitions. Typically, a logical partition has access to information relating to its own resources. However, at times, it is desirous to obtain information about resources as they relate to other partitions in the data processing system. In prior systems, this was accomplished by granting a logical partition global access to such information. That is, the logical partition is granted access to information pertaining to the resources for all of the logical partitions.
The restricted and global accesses of known systems have various pitfalls. For example, limited access is inadequate, since the logical partition can acquire information only about its own resources. Additionally, global access is inadequate, since a logical partition can acquire information relating to all of the logical partitions, even those requiring a higher security. Thus, a need exists for a limited global access mechanism in which access to logical partition information is restricted. A further need exists for a mechanism that allows information to be obtained about a resource as that resource relates to less than all of the logical partitions in a data processing system. A further need exists for the capability to limit the access of information to a per resource basis. A yet further need exists for a technique to provide greater flexibility in controlling access to logical partition information.